Oxidoreductases play important roles in living bodies, such as involvement in metabolism and energy production. In addition, oxidoreductases are extremely useful for industries, and are used for the measurement and calibration for the purposes of analysis and diagnosis. In recent years, oxidoreductases are used also in the field of bioenergy. For example, Patent Literatures 1 and 2 show the use of dehydrogenase formate, aldehyde dehydrogenase, and alcohol dehydrogenase in fuel cells operated with methanol.